1. Field of the Invention
The present invention relates to an agent for cleaning and dissolving dental calculuses or tartar (hereinafter simply called the tartar) of removable oral prostheses, which comprises a phosphonie acid base chelating agent or agents contained in water.
Removable oral prostheses serve in the mouth to recover occlusal, pronouncing and masticating functions, and are attachable thereinto or detachable therefrom by simple manipulation. Full or partial dentures are typically mentioned for that purpose. Materials consist of such prostheses may include porcelain, methacrylic resins, sulfone resins, gold alloys, silver alloys, gold-silver-palladium alloys, nickel-chromium alloys and cobalt-chromium alloys etc. While such oral prostheses are present in the mouth, dental plaque is deposited thereon under the influence of sputum, food residues, bacteria and so on, and is then calcified, leading to deposition of tartar on the oral prostheses.
Such deposits contaminate the prostheses per se. In addition, they not only worsen the oral environment, but are unpreferred for the health of a manipulator who corrects or restores the prostheses.
In order to maintain the oral health of a prosthesis-carrying individual, it is essentially required to remove plaque or tartar deposited thereon, and it is one of important manipulations for a dentist or a detal technician to remove plaque or tartar at the time of the correction or restoration of prostheses or regular examination. The present invention provides a composition for easily removing plaque or tartar on oral prostheses within a short time and without inflicting any damage thereon.
2. Statement of the Prior Art
Heretofore, cleaning agents designed to remove tartar deposited on the removable oral prostheses have relied upon (1) a polishing action, (2) a chemical action and (3) a combination of the polishing action with the chemical action.
According to the polishing type technique, tartar is removed by using a brush with finely divided silica, alumina, calcium phosphate and the like. This technique requires a longer period of time for removal of tartar, and may possibly wear out the prostheses. On the other hand, the conventional chemical type technique makes use of an aqueous solution containing peroxides, chloric acid compounds, EDTA, disinfectants, enzymes and so on. However, this technique is effective for removal of new tartar, but is uneffective for removal of old one. For that reason, the old tartar should be removed by immersing the corresponding prosthesis in an aqueous solution of an acid such as hydrochloric, acetic or phosphoric acid. However, this has the disadvantage of corroding and discoloring the metal forming the prosthesis.